M3the01

Trying to find some feedback on the dsc on gt2rs but can't find anything.

I really worry about the tune as it is the same across the 991 range. As anyone who had time in both the gt2rs and the gt3rs you know the suspension feels very different. This has to be a result of the factory controller as the springs and shocks are the same in the two cars. I don't want the gt2rs feeling like the gt3rs, the rear is set softer to get the power down and when it gets unsettled it performs a lot better.

I'm running 2.6f and 2.4r camber, rake balance (approx 2 turns lower in the rear accomplished the balanced rake), stock front ride height, e-motion tension arms and tie rods, running 34mm addition front track aka 17mm wider per front wheel. I'm using all the shim in the tension arm now but likely will still get a little front fender liner rub still... At least when I was running one shim less i was get fender liner rub up front, can't confirm i will still get it with all the shims.

I'm thinking of 130nm / 170nm springs and the dsc or going with whatever e-motion secret package is which is likely 130/170 for the gt2rs as that is what manthey used.

The car feels absolutely amazing besides the fender rub. There isn't much understeer anymore and the backend really whips around. Overall tire wear is also great, running Nankang AR-1s at the track.

Please lmk ur thoughts.

Ty

CaymanSinAR

I'd contact TPC Racing directly.

Tom from TPC Racing checks here often, and is a fountain of knowledge.

Do not be afraid to ring these guys with questions; they really know their stuff.

M3the01

Speaking to them but hoping for some real world feedback.

They have been great answering questions.

M3the01

Nothing?

pepinozaur

I wasn't that satisfied of the DSC on my former 991.2TTS running aftermarket springs... If your car feels so good, why change that? And why not adding some stiffer springs and skip the DSC.

I am kind of new to the GT2RS, I have ordered two complete sets of assorted shims from RSS, for front and rear. Are these going to give more or less the same front track and camber as your E-motion setup?

M3the01

Makes sense... i was thinking to just do the springs but is a smidge of work, lol, looking for the easy fix but not sold on the DSC non specific tune for the gt2rs. I get it, i can further adjust, but cant imagine releasing the same for gt3rs and gt2rs as they feel just so different from the factory and i dont want the gt2rs feeling like the gt3rs. I was close to grabbing those springs but figure i will do another track session with the additional shim to see if that helped.

Tom@TPC Racing

Just to share a data point for readers of this thread, the OEM PASM controller for 991.2 GT2RS and 991.2 GT3RS is the same part number.

M3the01

Very strange that they are the same... i assume u have driven both cars on and off the track? They feel completely different. The shocks, springs, sway bars are also the same. So what is the deal? Where does the abruptness of the 991.2 gt3rs come from? Given that it is slightly less weight than the gt2rs? I dont think so but i am extremely curious to know why they feel so different. Even cruising the bumps are harsher on the gt3rs. As porsche put it, the gt2rs is a bit more compliant vs the gt3rs given the increase power and top speed expectations. This makes sense as to keep the power transfer reasonable given some tracks being bumpy and would easily unsettle the car under power and high torque, which is exactly how it feels.

Something doesnt add up... it wouldnt make sense the tune on the controller is the same, maybe that is it? Has anyone swapped them from two cars?

Same point though, i appreciate the product and the ability to adjust but a standard tune across very different cars leaves a big margin for improvement.

Would luv someone with the DSC on the gt2rs to chime in...

Tom@TPC Racing

I have not driven the two cars in a back-to-back environment on the same day to compare the differences. Both cars to me are amazing street cars, even better when setup for track to the driver's preferences.

Perhaps, the difference you felt between the two cars is a result of difference in ride height setting, sway bar settings, tires(OEM Dunlop vs. OEM Michelin), alignment settings, or combination of all of the above. Just as an example on the ride height alone, 991-series cars are very sensitive to ride height changes, on the 991 Cup cars in competition a 3mm change can separate a front runner to a mid-pack car.

OEM spec ride height:
991.2 GT2RS 117/267mm
991.2 GT3RS 111/265mm

Using the OEM spec ride height for reference, the 6mm taller front ride height of the 2RS should theoretically result in a more compliant ride over bumps. So if someone were to lower a 3RS below OEM spec, say by 3mm, that would create a total difference of 9mm compared to OEM spec 2RS which then will result in a bigger difference in compliance feel. Lower ride height = the piston inside a damper being closer to the bottom of the damper = generally stiffer ride. Also, thinking outside of the suspension itself, how the engine torque loads the suspension results in a different behavior. Example here is a higher torque engine will compress the rear suspension at a higher travel velocity rate and unloads the front as well for different damping force output from the dampers. I first learned about this from tuning motorbikes a long time ago which some of the info is translatable to car dampers.

I wanted to clarify that the function of the DSC controller is more active than the OEM controller by having a wider control range that is reactive to the driver's inputs to manage weight distribution. The commands are not static in such a way that it makes one car feel like another car. Instead, it is active(or reactive or dynamic) to not feel static at all. I am not trying to push to sell another controller because they are already sold out for 8+ weeks with back orders...LOL

Tom@TPC Racing

Also, the heavier engine will preload the rear main spring a little bit more. Preloading the same spring differently and factoring the weight that the same spring is supporting will change the performance characteristics of the spring. I think I have mentioned this in a different thread in the past, it is pretty common in the motorsports industry to use the same damper/spring package for both NA and Turbo variant of the same chassis type. Examples go back to 964 and 993 era. Yes, I am old. LOL

nolimits

Because the OEM pn is same, do we know firmware, software config ... is same, or could loads and updates differ ?

Tom@TPC Racing

AFAIK the OEM suspension control unit is fixed programmed by the factory, which is why there are many different suspension controller part numbers with each part number designated to certain models(i.e. Carrera, S, GTS, Turbo, RS...). Factory updates, perhaps- would have to ask a dealer whether or not they have factory updates to change handling of the car.

The OEM suspension control unit is unlike the OEM engine control unit or the vehicle immobilizer unit that come blank and are designed to be programmed to the VIN by the dealer. The suspension unit is intended to be ordered by the VIN as a plug-in replacement.

Tom@TPC Racing

OP- another variable that can change compliance is FAL vs. non-FAL. The .2 cars with FAL come with shorter main springs to make up for the space that the hydraulic FAL unit occupies. Anyone who has played around with spring length/rates can attest that a longer length spring of the same rate will ride nicer over bumps
Below is a comparison pic of the springs. Check out the length difference and count the number of coils on the springs.

M3the01

Thanks to TPC for sharing some good info. Still hoping to have some gt2rs owners chime in... Even some gt3rs.2 would be helpful.